holmes



T. E. HOLMESJ CONTROLLING GEAR FOR HYDRAULIC FRESSESK' APPLiCATlON FILED SEPT. 19, 1919.

1,381,834, Patented June 14, 1921 2 SHEETSSHEET 1.

INVEN' R I T. vE, HOLMES.

CONTROLLING GEAR FOR HYDRAULIC PRESSES.

APPLICATION FILED SEPT. 19. 1919.

Patented June M 1W 2 SHEETSSHEEF 2.

UNirED STATES THOMAS EDMUND HOLMES, 0F GLASGOW, SCOTLAND.

CONTROLLING-GEAR FOR HYDRAULIC PRESSES.

Application filed September 19, 1919.

To all whom it may concern:

Be it known that I, THOMAS EDMUND IIoLMns, a subject of the King of Great Britain and Ireland, and a resident of Glasgow, Scotland, have invented certain new and useful Improvements in Controlling- Gears for Hydraulic Presses, and of which the following is the specification.

The invention relates to steam-hydraulic intensifier operated presses, shears and the like of the type in which the press head or equivalent part is raised by steam pressure and its rising controlled by a valve in the exhaust from the hydraulic cylinder or cylinders.

The invention has for its object to obviate either the use of trip mechanism in the gear controlling the steam valves of the lifting cylinders or of separate and independent devices for their controlboth hitherto common practice.

According to the invention, the valves controlling the steam supply to the lifting cylinders are so operatively connected to weights, springs or equivalents, that the valve controlling the exhaust from those cylinders is normally closed, while that controlling the inlet of steam to them is normally open. Thus there is normally exerted by the steam in the lifting cylinders a pressure tendingto raise the press head or equivalent part of the machine. The valve gear controlling the valves of the intensifier is of any convenient form and is operated by a usual han d-lever. This hand lever is so connected to the valves of the lifting cylinders through a lost motion device, that it moves them to open the exhaust and close the inlet at certain points in its range of movement against the pressure of the devices holding them in normal position, but at other points releases them so that they then reassume their normal positions-the exhaust valve closed and the inlet valve open.

The valve controlling the exhaust of pressure liquid from the hydraulic cylinder or cylinders of the press or the like is separately controlled, preferably by pedal.

The invention is applicable to apparatus of the general type shown in, my prior Patent No. 1,319,583, dated October 21, 1919, upon which the present arrangement is an improvement.

The improved controlling gear is shown on two accompanyin sheets of explanatory drawings Figure 1, best 1, being an eleva Specification of Letters Patent.

Patented June as, 19%1.

Serial No. 324,989.

tion of the lifting cylinder intensifier valve gear, while Figs. 2 and 8, Sheet 2, are an elevation and a plan respectively of part of the hydraulic cylinder exhaust controlling gear shown to a larger scale.

As shown in the drawings the inlet and exhaust valves A, B, of the liftin cylinders are controlled by a hand lever which is connected with a rod C by means of a tappet lever C operated by the hand lever C and engaging alternatively two tappets C C on the rod C The rod C is guided in the framing at one end, and at its other is connected to a bell-crank lever D which is connected by a link D with a rocking lever D The lever D is counterbalanced by a weight E and is connected by links E E to the valves A, B. The connection between the tappet lever C and the tappets C C is in the nature of a lost motion device, while the links E E have slots G, G in their upper ends within which work pins on the rocking lever D thus forming a second lost motion device. Weights D are also groligided on the spindles of each of the valves As shown in Figs. 2 and 3, the valve H controlling the exhaust of pressure liquid from the hydraulic cylinder is operated by a foot pedal J connected with one end of a link J by a bell-crank lever J the other end of the link J is connected by means of a lever K with a tappet lever K bearing on a spring controlled tappet K operatively connected to the spindle of the valve H.

In operation the exhaust valve B of the lifting cylinders is normally held closed by the weight D on the spindle of that valve, while the inlet valve A is normally held open by the rocking lever D Thus there is exerted by the steam in the lifting cylinders a pressure tending to raise the press head or equivalent part of the machine.

When the hand lever C is thrown over to the position shown in Fig. 1, the exhaust valve B is held open and the inlet valve A closed against the pressure of the weights holding them in normal position.

The valve II controlling the exhaust of pressure liquid from the hydraulic cylinder is operated against the action of the springcontrolled tappet K by means of the foot pedal J and the linkage connecting thls pedal with the tappet lever K What I claim is 1. A lifting cylinder control mechanism.

for hydraulic presses, comprising a normally open steam inlet valve, a normally closed steam exhaust valve, a hand lever and lost-motion devices operatively connecting the lever to the said steam valves to close the inlet valve and open the exhaust valve at one end of the lever stroke, and, at the other end of the lever stroke, to open the inlet valve and close the exhaust valve.

2. A lifting cylinder control mechanism for hydraulic presses, comprising a normally open steam inlet valve, a normally closed steam exhaust valve, a hand lever and lost-motion devices operatively connecting the lever to the said steam valves to close the inlet valve and open the exhaust valve at one end of the lever stroke, and, at the other end of the lever stroke, to open the inlet valve and close the exhaust valve, and means for automatically returning the hand lever and steam valves to their normal positions.

3. A lifting cylinder control mechanism for hydraulic presses, comprising a normally open steam inlet valve, a normally closed steam exhaust valve, a hand lever and lostmotion devices operatively connectingthe lever to the said steam valves to close the inlet valve and open the exhaust valve at one end of the lever stroke, and, at the other end of the lever stroke, to open the inlet valve and close the exhaust valve, in combination with a pressure liquid exhaust valve and pedal operated mechanism for controlling said valve.

4-. A lifting cylinder control mechanism for hydraulic presses, comprising a normally open steam inlet valve, a norn'ially closed steam exhaust valve, a hand lever and lost-motion devices operatively connecting the lever to the said steam valves to close the inlet valve and open the exhaust valve at one end of the lever stroke, and, at the other end of the lever stroke, to open the inlet valve and close the exhaust valve, in combination with a pressure liquid exhaust valve, a spring-stressed tappet connected thereto, a tappet-operating lever and a foot pedal control for said tappet lever.

In testimony whereof I have signed my name to this specification.

THOMAS EDMUND HOLMES. 

